Numerical studies of composite steel-concrete columns under fire conditions including cooling phase

Abstract

This work presents an analysis of the behaviour of composite steel-concrete columns under natural fires which include cooling phase. Thermo-mechanical numerical simulations based on the non-linear finite element method are conducted using the parametric fire model of Eurocodes to represent the natural fires. Results show that structural failure of the composite columns during or after the cooling phase of a fire is a possible event. The duration of heating phase (DHP) leading to the failure of structures during or after the cooling phase is always lower than the fire resistance of structures exposed to heating phase only. Parametric studies have been done to show the relationships between DHP and some major parameters such as load ratio, slenderness of column, eccentricity of load. This work enhances the understanding of the structural behaviour under natural fires.